Machine for wrapping helically split tubing



0d- 23, 1962 D. v. BENFER ETAL MACHINE FOR WRAPPING HELICALLY SPLITTUBING Filed Jan. 23, 1959 4 Sheets-Sheet l ll lfin INVENTORS Dawd. VBenfer and.

Robert B. Gardner Oct. 23, 19 D. v. BENFER ETAL 3,059,404

' MACHINE FOR WRAPPING HELICALLY SPLIT TUBING Filed Jan. 23, 1959 4Sheets-Sheet 2 INVENTORS. Davld V. Benfen' and Robert B. Gawdnev Jaw wwOct. 23, 1962 D. v. BENFER ETAL MACHINE FOR WRAPPING HELICALLY SPLITTUBING Filed Jan. 23, 1959 4 Sheets-$heet 3 INVENTORS. Davld V Benfevand Robert B. Gardner Oct. 23, 19 2 D. v. BENFER ETA]. 3,059,404

MACHINE FOR WRAPPING HELICALLY SPLIT TUBING Filed Jan. 23, 1959 4Sheets-Sheet 4 INVENTORS. Davld V. Benfev ant Robert B -Gardner UnitedStates Patent 3,659,464 MAC FOR PING HELICALLY SPLIT TUBING David V.Benfer, Marysville, and Robert B. Gardner,

Harrisburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Ian. 23, 1959, Ser. No. 788,634 1 Claim. (Cl. 57-6) This inventionrelates to a device for wrapping helically split tubing about one ormore wires or similar objects such as cables, tubing hoses, etc. to formwhat is known in the trade as a harness. See application S.N. 565,- 651;filed February 15, 1956, by William Wolfson.

It is an object of this invention to provide a machine for continuouslywrapping such tubing. It is also an object of this invention to providesuch a device wherein the tubing is uncurled prior to its applicationand such uncurling transmits a torque to the wrapping material to rotateit about the axis of the tubing as it is fed to the wires.

It is also an object of this invention to provide a balanced machine forsimultaneously feeding a number of spools of material.

It is also an object of this invention to provide a means for feedingthe wires which controls the pitch of the wrapped material as well asits tightness.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there is shown and described an illustrative embodiment of theinvention; it is to be understood, however, that this embodiment is notintended to be exhaustive nor limiting of the invention but is given forpurposes of illustration in order that others skilled in the art mayfully understand the invention and the principles thereof and the mannerof applying it in practical use so that they may modify it in variousforms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIGURE 1 is a perspective view of a machine illustrating the principlesof this invention;

FIGURE 2 is a spool of material adapted to be used in the machine shownin FIGURE 1;

FIGURE 3 is a fragmentary view of the device shown in FIGURE 1,illustrating the wrapping material feeding mechanism;

FIGURE 4 is a sectional view taken along plane 4-4 of FIGURE 3;

FIGURE 5 illustrates a bundle of wires with helical split tubing appliedthereto;

FIGURE 6 is a view taken along plane 66 of FIG- URE 1, partially brokenaway;

FIGURE 7 is a side elevation view similar to FIGURE 1 showing thewrapping assembly in section;

FIGURE 8 is a sectional view taken along plane 88 of FIGURE 7.

As shown in FIGURE 1 the device consists of three basic units, thedriving unit A; the wrapping unit B; and the feeding unit C.

The driving unit is comprised of a base member 10 which houses astandard power means 12 (e.g. electric motor) and if necessary, gearreduction means 14. The base member also supports a guide tube 16 fixedthereto which serves as part of the wrapping unit which will bedescribed later.

The feeding unit also includes a base 20 which houses a motor 22 andgear reducer 24. The base 20 supports an assembly 26 with a pair ofrotatable rollers 28, 28'. The upper roller 28 is driven by the powermeans 22 in a clockwise direction. A spring tensioning means 303,059,404 Patented Oct. 23, 1962 ice cause the lower roller 28 to engagethe upper roller 25 and thereby be driven by it in a counterclockwisedirection (as seen in FIGURE 1). Thus a bundle of wires W introducedinto the rollers from the direction of the guide tube 16, is caused tomove longitudinally in the direction indicated by arrow 30 in FIGURE 1.

Directing attention to FIGURE 7, the fixed tubing 16 has a rotatablecylinder 32 mounted with bearings 3 34' which permit it to rotate withrespect to the fixed tubing 16. The rotatable cylinder is disposed onone end of the fixed tubing 16 and has a sprocket 36 secured to the freeend. The sprocket is driven by a chain belt 38 which is connected to thegear reducer 14.

A material carrying member 40 is secured to the outer end of therotatable cylinder 32 and revolves therewith. The member 40 has a pairof arms 42, 42' extending radially outwardly. Since they are identical,only one of them need be described. However it is understood that anynumber of such arms may be employed. A material feeding opening 44 islocated near an extremity of the arm 42. A bearing 46 is secured to thearm adjacent to the opening 44 and has a material supporting hub orspindle 48 journalled to it. The hub 48 is attached to a supportingbracket 50 which retains a supply of wrapping material 52.

As shown in FIGURE 1, the support 50 has a crosspiece 53 with each end54 deformed at a right angle. A spring strap 57 joins the ends of thecross pieces so that a box of material 58 may be braced to the supportand retained therein by the spring straps. An opening 62 in the centerof the box (see FIGURE 2) permits feed from the coiled material. It isobvious (FIGURE 2) that the box of material may be used as a shippingcontainer and when ready for use the top flap 64 may be removed and thecarton applied to the support 50 and attached thereto by straps 57 asshown in FIGURE 7. The tubing may be fed from the coil 52, through thebearing 46 to the opening 44 in the arm 42.

A guide bracket 66 is also secured to the arm 42 on the opposite sidefrom the material supply 52. The guide bracket 66 extends in a directiontoward the material to be wrapped (in the illustrative embodiment use ofthe device on a bundle of wires W will be described). The guide brackethas a tubular member 68 (see FIGURE 4), secured thereto for aligning thetubing. A pin 71 is located at the free end of the guide bracket 66 sothat it is coaxial with the tubular member 68. The pin is formed by asmooth conical surface which tapers to a sharp point. The pin may berotatably disposed on the bracket by means of a ball bearing raceway 72.Also a roller bar 74 (FIGURE 3) is positioned on the bracket at rightangles to the pin.

When the machine begins operation it is desirable to deliver an initialimpetus to the support 50 so that it attains a rotational speedsomewhere near the rotational speed of the rotatable tubing 32.Otherwise the speed of the rotatable tubing, compared with the at restinertia of the support 50 will cause an abrupt tension on the helicallysplit tubing and tend to break it. After synchronism is achieved, thesupport 50 and tube 32 will continue to rotate harmoniously.

Conversely when the mechanism is stopped the tube 32 will be stoppedrather abruptly While the supports 50 continue to rotate freely.Accordingly a combination starter and brake for the supports 50 isprovided. This comprises a pair of arms 96, (FIGURE 7) with a rubber tip92, 92 which form brake shoes on each arm. In their at rest position thetips 92, 92 each bear against one of the supports 50 slightly off centerwith suflicient pressure to prevent free rotation of the support. Thearms extend through slots 94, 94 in a collar 96 which is fixedly securedto the arms 42, 42'. The slots on 94, 94' are sutiiciently wide topermit about relative rotation between the arms 99, 90' and the collar96, or an amount sufficient to permit the arm to rotate from a positionwherein it prevents rotation of the support to a position wherein it isclear of the support, note FIG- URE 8.

With the mechanism in the position shown in FZGURE 7, actuation of thedriving means 14 et a1. causes rotation of tube 32. The arms 90, 90'rotate about 15 before the support 42 starts to rotate. The action ofthe rubber tips 92, 92' moving from a position of compression againsttheir respective supports to the center poin. and then to positionswherein they are disposed from the support (FIGURE 8) delivers animpetus to the support which causes the supports to rotate. The arms 99and 99 drive the collar 96 and thus cause the arms 42, 42 to be rotatedby the drive means.

When the device is stopped the rotation of tubing 32 is prevented sothat coliar 96 will tend to continue to rotate due to inertia. This willcause the collar 96 to rotate relative to the lugs 91?, 90' so that theywill be aligned with the supports. The rubber tips 92, 92 willfunctionally engage the supports under compression so that they will actas a braking means to halt rotation of the supports. The brake shoes areof sufiicient length to pass over center relative to the supportstangent points holding the rubber tips under compression thereby lockingthe supports.

This arrangement provides a means for causing the spools of tubing tostart rotating prior to the rotation of the arms about the wire. Also itprevents the spools from freely rotating after the device is stopped.The tendency of the tubing to fracture because of a sudden jerk in thestarting or stopping cycle is thus eliminated.

Operation The wires to be assembled into a harness are fed into therotatable cylinder 32 and fed into the feeding rollers 28, 28'. Themotor 12 may be actuated by a foot switch S to rotate the cylinder 32via chain 38 and gear reducer 14. Rotation of the cylinder 32 alsocauses rotation of the arms 9!), 9t) fixed thereto. As previouslydescribed rotation of these arms gives the spools a rotational spin. Thelugs 90, 90 then drives the collar 96, arms 42, 42 etc.

The helical tubing may be drawn from the coil 52 through the opening 44,through guide tube 68, across the pin 70, and roller 72 and onto thewires W. The drawings illustrate concurrent feeding by two spools ofmaterial. However any number of spools, i.e. one or more may be used.Drawing the helically split tubing across the pin 70 causes it to uncurlso that it is in the form of a fiat strip 80 under tension and tendingto return to its helical form, something like a coil spring which isheld in an uncoiled position. As the material is rotated about the wiresit is permitted to return to its helical shape but since the outsidediameter of the bundle of wire is greater than the original insidediameter of the tubing, the material is tightly wrapped about the wires,note FIGURE 5.

A few turns of the material are applied to the wires before the machineis turned on. Thereafter the feed is continuous. The motor 22 drives therollers 28, 28'

to move the wires longitudinally through the path of the wrapping unit.The motor 14 drives the rotatable cylinder 32 to rotate the supply oftubing around the Wires in the direction shown by arrows 84 (FIGURE 6)to eifect the wrapping action. The tubing grips the wires so tightlythat longitudinal movement of the .wires pulls the tubing out of thecoil 52 to provide a continuous feed. The action of pulling the tubingacross the pin 79 not only prepares the tubing for the wrapping cyclebut transmits the torque resulting from uncurling the tubing backthrough the coil 52 so that the coil (and its assembly) rotates in thedirection indicated by arrows 86. This action of rotating the coil incombination with the longitudinal movement of the wires W effectsfeeding of the helically split tubing. Thus the arrangement not onlyprovides an outlet for bleeding oif the torque generated by uncurlingthe tubing but applies it to feed the coil thus eliminating the need fora separate feeding means.

By maintaining a constant speed rotation of the arm 42, the speed atwhich the wires are fed through the device may be varied to determinethe pitch of the wrapped material as well as how tightly it is bound tothe wires, alternatively the wire feed may be maintained as a constantand the speed of rotation varied to change the pitch, and tightness ofwrap or both may be varied according to the requirements of theparticular application.

As previously described when the device is shut down the relativerotation between the arms 90, 99 and the collar 96 permits the brakingaction to prevent free rotation of the spools.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is ofiered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claim when viewed in their properperspective against the prior art.

We claim:

A device for wrapping helically split tubing around elongated objectshaving a longitudinal axis in the 'direc tion of elongation, including:a base, means on said base for feeding the objects in the direction oftheir longitudinal axis, a rotary arm which revolves about the axis ofthe objects, rotary means on said arm for holding a supply of helicallysplit tubing, means for uncurling said tubing as it is fed onto theobjects, and means for rotating the means for holding a supply of tubingwhen the machine is initially started and to prevent such rotation whenthe machine is stopped.

References Cited in the file of this patent UNITED STATES PATENTS1,127,551 Vincent Feb, 9, 1915 1,526,572 Ten Eyck Feb, 17, 19251,808,444 Zapf June 2, 1931 1,956,730 Reichelt May 1, 1934 2,494,285Clapp Jan. 10, 1950 2,733,753 Schlesselman et al Feb. 7, 1956 2,813,392Woosey Nov. 19, 1 9 5 7

